Abstract
The presence of triiodide, I3–, throughout the lifetime of a persulfate–iodide reaction with persulfate in excess, is controlled by an opposing effect of falling iodide concentration and rising iodine concentration. This brings triiodide to a concentration maximum, [I3–]max, which can be studied by UV–visible spectroscopy using absorbance measurements taken over an extended iodine clock time-scan. Equilibrium and conservation equations can be combined so that, together with [I3–]max, a value of the constant K for the equilibrium established between iodine, iodide, and the triiodide complex ion can be obtained.
| Original language | English |
|---|---|
| Pages (from-to) | 814–816 |
| Number of pages | 3 |
| Journal | Journal of Chemical Education |
| Volume | 89 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2012 |
| Externally published | Yes |
Keywords
- Equilibrium
- Kinetics
- Reactions
- Upper-division undergraduate
- Analytical chemistry
- Laboratory instruction
- Physical chemistry
- Aqueous solution chemistry
- Oxidation/reduction
- UV−Vis spectroscopy